FlipFlop constructor

FlipFlop(
  1. Logic clk,
  2. Logic d, {
  3. Logic? en,
  4. Logic? reset,
  5. dynamic resetValue,
  6. bool asyncReset = false,
  7. String name = 'flipflop',
})

Constructs a flip flop which is positive edge triggered on clk.

When optional en is provided, an additional input will be created for flop. If optional en is high or not provided, output will vary as per inputd. For low en, output remains frozen irrespective of input d

When the optional reset is provided, the flop will be reset active-high. If no resetValue is provided, the reset value is always 0. Otherwise, it will reset to the provided resetValue. The type of resetValue must be a valid driver of a ConditionalAssign (e.g. Logic, LogicValue, int, etc.).

If asyncReset is true, the reset signal (if provided) will be treated as an async reset. If asyncReset is false, the reset signal will be treated as synchronous.

Implementation

FlipFlop(
  Logic clk,
  Logic d, {
  Logic? en,
  Logic? reset,
  dynamic resetValue,
  this.asyncReset = false,
  super.name = 'flipflop',
}) {
  if (clk.width != 1) {
    throw Exception('clk must be 1 bit');
  }

  addInput(_clkName, clk);
  addInput(_dName, d, width: d.width);
  addOutput(_qName, width: d.width);

  if (en != null) {
    addInput(_enName, en);
  }

  if (reset != null) {
    addInput(_resetName, reset);

    if (resetValue != null && resetValue is Logic) {
      _resetValuePort = addInput(_resetValueName, resetValue, width: d.width);
    } else {
      _resetValueConst = LogicValue.of(resetValue ?? 0, width: d.width);
    }
  }

  _setup();
}